有关u-turn

小胡同

最近查google map for directions, 经常会看到需要u-turn。印象之中好像在主路上不可以，不管是否有不可u-turn的牌子。平常也看到有人在红绿灯处做u-turn。
请问u-turn到底是不是合法的？
谢谢！

EightBelow

U-turns
/ p! G: _  C9 k0 v: i' g/ Q& G# ~• Do not make a U-turn unless you can do it safely and without interfering
with other traffic.
• Outside urban areas U-turns are not permitted on a curve or near the
8 `% F. E' c( Xcrest of a hill where the driver of another vehicle cannot see your vehicle.
U-turns are not permitted in urban areas in the following situations:
- l+ @/ Q$ }  T, |• On a roadway between intersections.
• Where a sign prohibits making a U-turn.
• At an intersection controlled by a traffic-control signal (traffic lights).
: v+ J6 b& u. r' s• At an alley intersection.

无语

有红绿灯的地方U-Turn是违规的。